The point of the second suggestion was not to devalue old
nodes, but rather to help people searching the archives
judge which answers to a question are the best - if you
don't know about a subject, you will have difficulty telling the difference between a good answer and a great answer - though I imagine the really bad answers will tend to speak for themselves (or have helpful followups)

It would just be a helpful cue to people who are new here or who are new to a subject as to which answers in the archives are the best or most helpful (or at least, those that other people think are the best or most helpful :-)

I must admit, I'm with kudra on this one.
I often search for answers to problems I'm experiencing, and that search often leads me to old nodes. If I find something that I think is insightful and/or particularly good, then I will vote ++ for it.
I see your point about being able to see the results of the voting and agree that it would be useful if you are trying to gauge the 'importance' of a node, but I think withdrawing the ability to vote on that node will just remove the ability for a monk to show his appreciation to the author.
As you suggest I think that the 'greatness' of the node can be gauged by the comments attached to it and the reader, whether a newbie or not, should be able to judge for themselves.

Ah, I see what's meant now. It may be valid to show reputation
and still allow voting for older nodes. After all, if you've
spent the time to trawl through the archives looking for
an answer to a problem, and you find exactly what you
are looking for, you are likely to vote it up whether or
not it had a high reputation to begin with. Voting a node
up is also a way of commenting on it.

Hrm, one of the disadvantages of the current voting system
is that nodes posted very recently to front-page items
tend to get voted up a lot more than (possibly better)
nodes posted later on. I tend to go back to discussions
I voted on previously to check if any new nodes have better
answers, and I often note that an average, but early, answer
gets +20 or something, and a later, but better, answer tends
to only get around +6 (in fact, +6 seems remarkably common...).
It may be an idea to allow higher-level monks to vote
older nodes +2 if they turn out to be particularily good.